The invention generally relates to interpolating seismic data.
Seismic exploration involves surveying subterranean geological formations for hydrocarbon deposits. A survey typically involves deploying seismic source(s) and seismic sensors at predetermined locations. The sources generate seismic waves, which propagate into the geological formations creating pressure changes and vibrations along their way. Changes in elastic properties of the geological formation scatter the seismic waves, changing their direction of propagation and other properties. Part of the energy emitted by the sources reaches the seismic sensors. Some seismic sensors are sensitive to pressure changes (hydrophones), others to particle motion (e.g., geophones), and industrial surveys may deploy only one type of sensors or both. In response to the detected seismic events, the sensors generate electrical signals to produce seismic data. Analysis of the seismic data can then indicate the presence or absence of probable locations of hydrocarbon deposits.
Some surveys are known as “marine” surveys because they are conducted in marine environments. However, “marine” surveys may be conducted not only in saltwater environments, but also in fresh and brackish waters. In one type of marine survey, called a “towed-array” survey, an array of seismic sensor-containing streamers and sources is towed behind a survey vessel.
In exploration seismology, although the time coordinate is regularly or non-uniformly, sampled, spatial coordinates are typically irregularly, or non-uniformly, sampled due to the presence of obstacles in the land environment or strong currents that are present in the marine environment. Thus, for example, for the marine environment, even with the latest steering technology, it may not be possible to maintain the streamers parallel to each other. Furthermore, the seismic sensors in a given streamer may not be equidistantly spaced apart. Hence, the inline sampling may also be quite non-uniform.
The regularization of seismic data typically is very important, especially in time-lapse survey matching, multiple suppression and imaging. If the irregular nature of the sampling grid is ignored or handled poorly, notable errors may be introduced, and the errors may be further amplified at later stages of the seismic data processing chain.